Carburetor



Feb. 22, 1949.

Filed June 23, 1945 F. D. WARBURTON 2,462,696

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Patented Feb. 22, 1949 UNITED STATES PATENT OFFICE CARBURETOR Frank D. Warburton, South Gate, Calif.

Application June 23, 1945, Serial No. 601,259 2 Claims. (01. 261-51) This invention has to do with carburetors.

It is among the aims of my invention to provide a carburetor of extremely simple and economical design which requires no float, which affords highly efficient admixture of the fuel with the incoming air stream, which requires a minimum of parts, and which eliminates the necessity of the frequent adjustments required in conventional carburetors.

Another shortcoming of conventional carburetors is the occurrence of flat spots at the commencement of acceleration due to the sudden opening of the butterfly valve before the fuel supply to the air passageway reaches adequate proportions.-

It is therefore one of the principal aims of my present invention to provide a carburetor embodying means for preventing such flat spots that is, my present invention provides a fuel supply booster which is automatically and momentarily operable at the commencement of acceleration.

Other objects will appear hereinafter.

For the purpose of making my invention better understood I shall now describe one of its preferred embodiments wherein Ishall refer to the accompanying drawings, in which:

Fig. 1 is a medial vertical section;

Fig. 2 is a view partly in side elevation and partly in section as denoted by the line 2-2 of Fig. 1;

Fig. 3 is a view taken on line 33 of Fig. 1;

Fig. 4 is a view taken on line 4-4 of Fig. 1;

and

Figs. 5 and 6 are enlarged fragmentary sections.

Referring to the drawings, the numeral 5 denotes the body, which has a round axial passageway 6 therethrough and is adapted to be secured to the intake-of an internal combustion engine by means of the attaching flange I. The medial portion of the body is of squared cross section while the upper and lower end portions are of round cross section. The passageway has a top end portion of relatively large diameter and a bottom end portion of reduced diameter, said portions intersecting each other in a beveled annular shoulder providing a throat 9.

' The passageway is controlled by a butterfly site end of the shaft acts to rotate the shaft.

in one direction. ;The spring draws the shoulder 2 against the body only sumciently to yieldably oppose free rotation of the shaft.

Also disposed transversely through and journaled in the body adjacent the throat 8; there is a shaft having a shoulder 26 bearing against the body. On the opposite end of the shaft 25 there is a sleeve 28 whichcarries onits inner end a flange 30 whose inner-face rotatably bears against the flat face 3| of the squared portion of the body. The sleeve 28 isl'a'xially slidable'upon the shaft 25 but is held against rotation relative thereto by means of a collar 33 which is fixed to the shaft but has an ear 34 engaging in-a slot 35 in the sleeve. A cap 31 is secured on the left-hand end of the shaft by a cap screw 39 and a compression spring 40 bears at one end against the cap and at its other and against the flange 30.

A cup is secured to the body in sealing engagement therewith by cap screws extending through its attaching flange (not shown) and threadedly engaging in the body, the outer end of the cup having an opening 46 into which a fuel suppy conduit 48 is threaded. The conduit 48 leads from a fuel source not shown so that in with fuel P at 50a. Passageway 5| is the main fuel supply passageway communicating with the passageway 6 through a spray member 5| 11 having a plurality of downwardly disposed orifices 5 lb. Passageway 52 is the booster fuel passage communicating with the passageway 6 as shown at 52a.

As will be seen best in Fig; 4, the flange 30 has an eccentric peripheral portion adapted, upon rotation of the sleeve, to gradually cover and uncover the main fuel passageway 5|; has a peripheral projection 62 which is positioned to partially cover the idling fuel passage 50 when the carburetor is in idling position. The adjacent peripheral portion of the flange is circular, terminating in a shoulder 65 which is circumferentially spaced from the projection 62 so that limited rotational movement of the flange is possible without closing the idling fuel passage 50.

As best shown in Figs. .4 and 5, the booster passage 52 is normally maintained closed by a spring-loaded ball valve 10 which is held against against the stop pin 16, likewise carried by the boss, by a spring I1. Consequently, the pawl is free to swing about its pivotal mounting when the sleeve is rotated counterclockwise or in throttle-closing direction, but when the sleeve is rotated clockwise to open the throttle, it encounters the stop and thus depresses the ball by cam action as it passes thereover.

For rotating the shafts l6 and 25, an arm 80.

is rotatably mounted on shaft IS, the outer end of the arm being pivotally connected to the conventional actuating link 8| at its outer end 80a. An arm 82 is fixed on shaft 25, the latter arm being operatively connected to arm 80 by means of a link 84 so that both arms 80, 82 swing in unison. In arm 80 there is an arcuate slot 85 disposed circumferentially of shaft. l6 and fixed on the latter shaft there is a collar 86 carrying a pin 81 which projects into the slot for movement between the ends of the slot to permit a limited amount of lost motion. The purpose of this lost motion is explained as follows: In opening the throttle the shaft 25 is rotated relative to the shaft l6 until the pawl 13 engages the ball Ill to start opening of the passageway 52. Thus the butterfly valve does not commence its opening movement until the booster passage opening is commenced and booster fuel delivered to passageway 6. n the closing operation, the. lost motion described permits the projection 62 to move into position partially closing the idling passageway after the butterfly valve has been closed and permits an adjustment such that the butterfly valve may be left slightly open.

The shaft 16 is adjustably limited in its closing movement by a stop screw 90 (see Figs. 2 and 3) threaded into boss 9| carried by the body, the inner end of the screw being positioned to engage a radial arm 92 carried by a collar 93 fixed on shaft IS. The extent of the closure of the idling passage by projection 62 may be regulated by the adjustable stop screw 94 threaded into an angled portion 80b of arm 80 for engagement with boss 9|, which adjustment also determines the amount of movement of flange 30 after the butterfly valve is closed. Both stop screws 90 and 94 carry compression springs to lock the against vibrating out of set position.

Operation is as follows: To open the throttle, the actuating link 8| is moved to swing arm 80, which in turn initially rotates shaft 25 along until the pawl 13 engages ball 10. At this point the lost motion pin 81 engages an end of the arcuate slot 85 and thus further movement of link 8| causes the shafts I5, 25 to rotate in unison, resulting in the gradual opening of main fuel passage 5| by virtue of the eccentric peripheral portion 60 of the flange 30 as well as the closing of the idling passage 50. To close the throttle the link 8| is moved in the opposite direction, first causing the flange 30 to gradually close the main fuel passageway 5|, simultaneously opening the idling bypass 50, and then moving the projection 62 into position partially closing the idling passage 50. Thus it will be observed that immediately prior to opening, of the butterfly valve, a booster charge of fuel is momentarily discharged into the air passage 5 above the butterfly valve so that, upon opening the butterfly, there is an extra supply of fuel.

I claim:

1. In a carburetor, the combination of-a body having an air passage therethrough and a fuel supply chamber, a first shaft journaled in the body and disposed transversely of the air passage adjacent the outlet end thereof, a butterfly valve carried by the shaft to control the air passage, a second shaft journaled in the body and disposed tranversely of the air passage between the inlet end thereof and the first-mentioned shaft, one end of the second shaft projecting into the fuel supply chamber through a side wall thereof, a main fuel feed port and a booster fuel feed port in the body, each opening at one end into the fuel supply chamber through said side wall and communicating at its other end with the air passage, a sleeve axially slidably mounted on the second shaft within the fuel supply chamber, means preventing rotation of the sleeve relative to the second shaft, a disc-like valve fixed on the inner end of the sleeve and rotatably bearing against said side wall in normal covering relationship to the main fuel feed port, said disclike valve having an eccentric peripheral portion adapted upon rotation thereof to gradually open and close said main fuel feed port, means carried by the disc-like valve to control the booster fuel feed port, said means being operable in response to initial rotation of the disc-like valve in a direction which will open the main fuel feed port to momentarily open the booster fuel feed port, and means for rotating the shafts, said last-named means having a lost motion connection to the first shaft and a fixed connection to the second shaft whereby to cause limited initial rotation of the disc-like valve before actuating the butterfly valve.

2. In a carburetor, the combination of a body having an air passage therethrough and a fuel supply chamber, a first shaft journaled in the body and disposed transversely of the air passage adjacent the outlet end thereof, a butterfly valve carried by the shaft to control the air passage, a second shaft journaled in the body and disposed transversely of the air passage between the inlet end thereof and the flrst-mentioned shaft, one end of the second shaft .projecting into the fuel supply chamber through a side wall thereof, a main fuel feed port and a booster fuel feed port in the body, each opening at one end into the fuel supply chamber through said side wall and communicating at its other end with the air passage, a sleeve axially slidably mounted on the second shaft within the fuel supply chamber, means preventing rotation of the sleeve relative to the second shaft, a disclike valve fixed on the inner end of the sleeve and rotatably bearing against said side wall in normal covering relationship to the main fuel feed port, said disc-like valve having an eccentric peripheral portion adapted upon rotation thereof to gradually open and close said main fuel feed port, a spring-loaded ball check valve normally closing the booster fuel feed port, pawllike cam means swingably carried by the disclike valve, said cam means being operable in response to initial rotation of the disc-like valve in a direction which will open the main fuel feed port to momentarily engage and move the ball check valve off its seat and being swingable in response to rotation of the disc-like valve in the reverse direction whereby to pass over the ball REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date H ppisley Oct. 1'7, 1911 Southern Apr. 11, 1916 Gretz Dec. 10, 1940 Trussell Aug. 11, 1942 Snyder Mar. 16, 1943 McCurdy July 20, 1943 FOREIGN PATENTS Country Date Germany May 8, 1930 

